1. Field of Invention
This invention relates to methods and apparatus for providing private e-mail service, where “private” means protected against unwanted disclosure during and after delivery.
2. Description of Related Art
In conventional e-mail systems, when an e-mail message is sent to a receiving party, the e-mail message must be routed through a chain of relay servers using Simple Mail Transfer Protocol (SMTP). These servers routinely back-up these e-mail messages to back-up storage devices such as hard disks or magnetic tapes. Therefore, when conventional e-mail is deleted, it is not totally destroyed, it is simply not readily available to the person deleting it. The e-mail message may continue to exist on the receiving mail server, and ultimately on backup tapes. These backup tapes, which may contain sensitive e-mail messages, are thus susceptible to retrieval by outside parties. Even if the e-mails recorded on the tapes are encrypted, they might still be recovered if the encryption/decryption keys are compromised, i.e., revealed. Conventional e-mail systems do not guarantee privacy, that is, protection from unwanted disclosure after delivery. Thus, there is a need for new technology which can provide an off-the-record manner in which to send and receive private e-mail messages.